--- Maarten buis <[email protected]> wrote:
> You can see graphs of such bimodel beta distribution in the example
> below.
Actually that code contained a minor error in the calculation of the
constant. It does not change the shape, so the message from these
graphs doesn't change, but the correct code is below:
*-------------------- begin example ----------------
/*conventional parameterization*/
twoway function y = betaden(.5, .7, x)
/*alternative parameterization*/
local phi = 1.5
local mu = .5
local constant = exp(lngamma(`phi'))/ ///
(exp(lngamma(`mu'*`phi'))*exp(lngamma((1-`mu')*`phi')))
twoway function y = `constant'* ///
x^(`mu'*`phi'-1)* ///
(1-x)^((1-`mu')*`phi'-1)
*-------------------- end example ------------------
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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